MOUNTAIN VIEW, Calif.--News aggregation, licensing rights, and user-generated content. Every publisher has grappled with one or all of these issues as they've built online operations in the age of social media.

They're also potentially ripe markets for innovation. Or at least that's the hope of four Web publishing start-ups that presented business models here Tuesday at the Under the Radar Conference, a one-day confab on social media.

Four companies--AudioMicro, GumGum, Keibi, and Loud3r--delivered a six-minute elevator pitch to an audience of executives and three judges. Judges included Charlene Li, vice president at Forrester Research; Rob Hayes, partner at First Round Capital; and Jason Oberfest, vice president of business development at MySpace.

Here are the online publishing hopefuls:

AudioMicro
What it does: licenses music or soundtracks for $1. Launched last week, the company hosts a marketplace for independent artists to upload and license their music for $1. People who've produced a YouTube video, for example, could license an audio track from AudioMicro's collection of artists to sync the music with their video. Or movie studios could use the site to find music and offset production costs, according to founder Ryan Born. "We crowd-source content from unknown artists around the world and sell it for a dollar," Born said during his elevator pitch.

But First Round Capital's Rob Hayes pointed out that the company has a chicken-and-egg problem. It needs artists to attract major licensors, and it needs major licensors to attract artists.

AudioMicro, based in Los Angeles, is looking to raise a series A round of funding to grow fast and market itself.

GumGum

GumGum
What it does: Flexible licensing of photos, text, and video over the Internet. GumGum, which was founded in February, has created a marketplace for content--audio, pictures, articles, and video--that publishers can license per use, or for a share of advertising revenue. (Independent content creators post their material on GumGum, which is based in Santa Monica, Calif.) "We aggregate, post, and distribute content via widgets," according to the founders.

Gawker, for example, can pick up a cut of code for a photo on GumGum and paste it to its site, then pay a set price each time that photo is viewed from its site. Or it could allow GumGum to wrap an ad around the photo and collect 20 percent of the revenue. Gawker is an early public customer.

The challenge? Adoption.

Keibi
What it does: Technology for moderating user-generated content on sites like MySpace and Facebook. The two-year-old company is trying to solve one of the biggest problems that social networks face--how to make major brands comfortable with advertising near potentially questionable content posted by members of these networks. Keibi's answer is to sell an enterprise software platform that helps social networks moderate photos, text, images, or video before they're posted to a site.

Jason Oberfest (of MySpace) and one of the judges asked how well it integrates with social networks' existing software infrastructure. Paul Remer, CEO of Keibi, said that it has a plug-in and is working with companies like Salesforce.com on integrating its technology.

Keibi charges customers between $2,000 and $20,000 a month to use its software-as-a-service platform. So far, the company has raised $6 million; and it's in the process of raising a series B round of financing, Remer said.

Loud3R

Loud3r
What it does: news sites for sneaker heads, dog lovers, and martial arts geeks. And that's just a drop in the bucket. Loud3r develops technology to scour the Web for specialized news and social content, and then aggregates that material into a branded Web site. It owns 25 different sites--New3R (for gadgets and technology), Glaci3r (environment), and Putt3r (for golf)--but it plans to have at least 250 by the end of 2009. The company plans to make money by selling brand advertising around its targeted topics, and license its technology to third parties for five figures monthly.

"The Internet is a noisy place. Loud3r is the solution for the noise," said Lowell Goss, founder and CEO.

Still, the judges were skeptical about whether the Web needs another news aggregator. One judge asked specifically if Loud3r is late to the party. Lowell's answer: "Google wasn't the first search engine."